PTFE Tape or Thread Sealant on Plastic pipe fittings?
August 2nd, 2009 | 
Author: I’m assembling a solar pump system using 2" polypipe with a mixture of 11/4" and 2" plastic pipe fittings. We’re pumping from one dam (pond) to another dam about 20m head. Would it be recommended to use regular PTFE tape or some kind of thread sealant. And if the tape, how much should I use. Some people say 3-4 wraps, but does that mean 3-4 layers of thickness, or the number of turns you do from the start. I’ve also seen some people say 3-4 layers thick. Cheers
Ken is right about the stress cracks, I’ve seen it first hand. I use both, just a couple wraps/layers and then TFE paste with teflon. Hope this helps, and good luck.
Posted in Solar Pond Pump
The best thing to use is a pvc compatible pipe thread compound. I’ve included a link to a manufacturers page. Tape tends to deform threads by adding extra thickness which will cause stress cracks over time.. Plastic threads are infamous for breaking, it’s usually due to poor installation methods.
Good Luck!
References :
http://www.spearsmfg.com/how_to/FG-3B-0105_0706_English.pdf
2 wraps on plastic is fine.PTFE is a good choice.
References :
teflon paste. the best, it works great with all plastics.
References :
Ken is right about the stress cracks, I’ve seen it first hand. I use both, just a couple wraps/layers and then TFE paste with teflon. Hope this helps, and good luck.
References :